Improvements in building construction have resulted in wall assemblies that are highly energy efficient. These wall assemblies are often highly insulated and include sealed joints around windows and doors to prevent drafts. While these walls have high thermal efficiency, it has been observed that moisture can potentially accumulate inside the wall over time due to naturally occurring temperature and/or humidity gradients. In addition, moisture can potentially accumulate inside sealed walls due to water running down a steeply pitched roof, for example in the case where the joint/seal between the wall and the roof deteriorates and provides an ingress location for water into the wall.
Moisture trapped inside of the walls includes moisture vapor and bulk water, such as condensation. Condensation can form inside a wall due to temperature differences across the insulated walls. For example, during typical northern cold winter months, the air outside of an insulated wall is cold and dry, and the air inside of the wall is relatively warm and humid. Thus, a natural humidity gradient is formed that drives moisture vapor in the air inside the wall toward the exterior of the wall. Large gradients between outside and inside air temperature and humidity can lead to a significant accumulation of moisture condensation within the insulated wall. Exterior wall systems can employ drainage features, such as weep holes, for example, that can be aesthetically unacceptable. Often exterior insulation and finish systems (EIFS) do not include drainage features, and particularly, do not include aesthetically acceptable drainage features to divert water from a drainage plane of an exterior wall system.